@article{HelsperDreilingHalleretal.1986,
  author    = {Helsper, Christoph and Dreiling, V. and Haller, P. and Kaminski, U.},
  title     = {Intercomparison of Eleven Condensation Nucleus Counters / Dreiling, V. ; Haller, P. ; Helsper, C.; Kaminski, U. ; Plomp, A. ; Raes, F. ; Roth, C. ; Schier, J. ; Sch{\"u}rmann, G.},
  series = {Journal of Aerosol Science. 17 (1986), H. 3},
  journal   = {Journal of Aerosol Science. 17 (1986), H. 3},
  isbn      = {0021-8502},
  pages     = {565 -- 570},
  year      = {1986},
  language  = {en}
}
@article{HelsperMoelterHaller1990,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Haller, P.},
  title     = {Representative Dilution of Aerosols by a Factor of 10,000},
  series = {Journal of Aerosol Science. 21 (1990), H. Suppl. 1},
  journal   = {Journal of Aerosol Science. 21 (1990), H. Suppl. 1},
  isbn      = {0021-8502},
  pages     = {637 -- 640},
  year      = {1990},
  language  = {en}
}
@article{HelsperWiedensohlerWeiseetal.1986,
  author    = {Helsper, Christoph and Wiedensohler, A. and Weise, W. and L{\"u}tkemeier, E.},
  title     = {Determination of the Bipolar Charge Equilibrium in Pure Gases / Wiedensohler, A. ; Weise, W. ; Helsper, C. ; L{\"u}tkemeier, E.},
  series = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  journal   = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  publisher = {Pergamon Press},
  address   = {Oxford [u.a.]},
  pages     = {383 -- 386},
  year      = {1986},
  language  = {en}
}
@article{HelsperLuetkemeierWiedensohler1986,
  author    = {Helsper, Christoph and L{\"u}tkemeier, E. and Wiedensohler, A.},
  title     = {Charge Distribution by Unipolar Charging of Small Aerosol Particles / L{\"u}tkemeier, E. ; Helsper, C. ; Wiedensohler, A.},
  series = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  journal   = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  publisher = {Pergamon Press},
  address   = {Oxford [u.a.]},
  pages     = {474 -- 478},
  year      = {1986},
  language  = {en}
}
@article{Helsper1986,
  author    = {Helsper, Christoph},
  title     = {Measurement Techniques For Ultrafine Particles},
  series = {Ultrafine aerosols. Properties and behaviour. Proceedings of the 1. International Workshop on Ultrafine Aerosols of the Sonderforschungsbereich 209 'Stoff- und Energietransport in Aerosolen' -'Mass and energy transfer in aerosols'-, held at the Univ. of Duisburg on Sept. 29, 1986},
  journal   = {Ultrafine aerosols. Properties and behaviour. Proceedings of the 1. International Workshop on Ultrafine Aerosols of the Sonderforschungsbereich 209 'Stoff- und Energietransport in Aerosolen' -'Mass and energy transfer in aerosols'-, held at the Univ. of Duisburg on Sept. 29, 1986},
  address   = {Duisburg},
  year      = {1986},
  language  = {en}
}
@article{HelsperMoelterWillemer1987,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Willemer, W.},
  title     = {Fast and Automated Testing of Filter Media / M{\"o}lter, W. ; Helsper, C. ; Willemer, W.},
  series = {FILTECH Conference 1987 : Utrecht, Holland; September 23 - 25 1987 / org. by the Filtration Society , Vol. 1.},
  journal   = {FILTECH Conference 1987 : Utrecht, Holland; September 23 - 25 1987 / org. by the Filtration Society , Vol. 1.},
  publisher = {Filtration Society},
  address   = {Loughborough},
  pages     = {106 -- 112},
  year      = {1987},
  language  = {en}
}
@article{HelsperMoelter1989,
  author    = {Helsper, Christoph and M{\"o}lter, L.},
  title     = {Erzeugung von Pr{\"u}faerosolen f{\"u}r die Kalibrierung von optischen Partikelmeßverfahren nach VDI 3491},
  series = {Technisches Messen. 56 (1989)},
  journal   = {Technisches Messen. 56 (1989)},
  isbn      = {0171-8096},
  pages     = {229 -- 234},
  year      = {1989},
  language  = {en}
}
@article{HelsperMoelterKaminski1989,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Kaminski, S.},
  title     = {Fast and Automated Testing of Different Air Filter Media / M{\"o}lter, W. ; Helsper, C. ; Kaminski, S.},
  series = {1. Europ{\"a}isches Symposium Partikelabscheidung aus Gasen : [PARTEC, N{\"u}rnberg, West Germany, 19. - 21. April 1989 ; preprints] = 1. European Symposium Separation of Particles from Gases / [Organisation und Durchf{\"u}hrung: N{\"u}rnbergMesse]. Hrsg. von: Friedrich L{\"o}ffler},
  journal   = {1. Europ{\"a}isches Symposium Partikelabscheidung aus Gasen : [PARTEC, N{\"u}rnberg, West Germany, 19. - 21. April 1989 ; preprints] = 1. European Symposium Separation of Particles from Gases / [Organisation und Durchf{\"u}hrung: N{\"u}rnbergMesse]. Hrsg. von: Friedrich L{\"o}ffler},
  publisher = {N{\"u}rnbergMesse},
  address   = {N{\"u}rnberg},
  pages     = {441 -- 457},
  year      = {1989},
  language  = {en}
}
@article{HelsperMoelterKaminski1989,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Kaminski, S.},
  title     = {Fast and Automated Testing of Different Air Filter Media / M{\"o}lter, W. ; Helsper, C. ; Kaminski, S.},
  series = {Proceedings of the Filtech Conference, Karlsruhe 1989, Vol. 1},
  journal   = {Proceedings of the Filtech Conference, Karlsruhe 1989, Vol. 1},
  publisher = {Filtration Society},
  address   = {Oadby},
  pages     = {125 -- 136},
  year      = {1989},
  language  = {en}
}
@article{HelsperMoelter1991,
  author    = {Helsper, Christoph and M{\"o}lter, W.},
  title     = {Characteristics of a Nebulizer with Cyclone Preseparator / M{\"o}lter, W. ; Helsper, C.},
  series = {Aerosols, their generation, behaviour and applications. Annual Conference of the Aerosol Society / Aerosol Society (UK) ; 5.},
  journal   = {Aerosols, their generation, behaviour and applications. Annual Conference of the Aerosol Society / Aerosol Society (UK) ; 5.},
  address   = {Loughborough},
  pages     = {89 -- 94},
  year      = {1991},
  language  = {en}
}